It is usual within rapidly growing technical fields to provide a user unit, such as a telephone for instance, with additional equipment that has been produced subsequent to the production of the user unit. When there is no or little support for later produced equipment, the additional equipment and other auxiliaries function to only a limited extent with the earlier produced user unit, or sometimes not at all. When there is a need to be able to use later produced additional equipment with the older user unit, it is necessary to be able to operate the additional equipment from the user unit. This presents a problem, of course, since the additional equipment was not known at the time of producing the user unit.
Telecommunications is an example of the aforementioned technical field, and a telephone that includes a display is one example of a device. U.S. Pat. No. 5,488,650 teaches a system that allows a telephone user to create a menu of his/her choice for an accessory unit connected to the telephone, by pressing appropriate buttons on the keypad. The drawback with this solution is that it requires the user to contribute actively towards creating the menu.
U.S. Pat. No. 5,430,793 teaches a method of configuring a computer system for use in different countries with different telecommunications systems, and logic for displaying in the computer system an options menu that adapts to the telecommunications system used on that occasion. The drawback with the invention disclosed in this publication is that it is necessary to pre-store those telecommunications systems to which the computer system can be connected. This excludes future telecommunications systems that were not known at the time of storing said possible telecommunications systems.